An item with an integral porous or perforated plate, or with slits on the inside of a double wall.
NSN 5915-01-497-6307
NSN 5910-00-060-4638
NSN 6150-00-137-9802
NSN 6320-00-483-0451
NSN 6145-01-533-5559
NSN 5895-00-138-3749
NSN 5935-00-258-3034
NSN 6620-01-030-6495
NSN 6220-01-085-0841
NSN 6135-01-322-4655
NSN 6220-00-257-5183
NSN 6130-01-656-4766